Fluid inflatable seal

ABSTRACT

A fluid inflatable seal for use between the cover and base of a heat treating furnace. The seal includes an annular fluidimpervious member mounted on the base. Valves are provided to inflate and deflate the annular member. In the inflated position, the annular member extends between the cover and the base to provide a fluidtight seal. The casing of the member is made of a nonelastomeric material, and optionally strips of relatively yieldable material are secured to the casing to abut against both the cover and the base for good sealing characteristics.

United States Patent 2,725,643 12/1955 Ransohofl' CalvinC. Blackman Inventor 24272 W. Lake Road, Bay Village, Ohio 44140 Appl. No. 842,208 Filed July 16, 1969 Patented July 20, 1971 FLUID INFLATABLE SEAL 8 Claims, 4 Drawing Figs.

US. Cl 263/49, 277l34.3,266/5,-34/242 lnLCl Q ..F26b 25/00, F27d 23'/00,C21dl/12, F16j 15/46 Field of Search 277/34,

References Cited UNITED STATES PATENTS 2,832,618 4/l958 Knoll et a1. 277/34.3 3,179,394 4/1965 Sims et a1 t 1 263/49 943,023 12/1909 Johnson 1, 277/34 3,471,137 10/1969 Kitchel 266/5 B Primary Examiner-esamuel Rothberg Attorney-William N. Hogg ABSTRACT: A fluid inflatable seal for use between the cover and base of a heat treating furnace. The seal includes an annular fluid-impervious member mounted on the base. Valves are provided to inflate and deflate the annular member. in the inflated position, the annular member extends between the cover and the base to provide a fluidtight seal. The casing of the member is made of a nonelastomeric material, and 015- tionally strips of relatively yieldable material are secured to the casing to abut against both the cover and the base for good sealing characteristics.

FLUID INFLATABLE SEAL BACKGROUND OF INVENTION The use of bell-type annealing furnaces for heat treating coiled strips of material has become widespread in the art. These heat treating furnaces include a base of one or more pedestals on which the coiled strips of material which are to be heat treated are placed. An inner cover is placed over these coiled strips of material, and it is necessary in most instances to seal the coils within the inner cover to provide a controlled atmosphere therein.

An improvement on this bell-type annealing furnace is shown in patent application, Ser. No. 857,253 filed July 16, 1969 entitled Metallurgical Furnace which is a continuationin-part of application Ser. No. 750,830 filed Aug. 7, 1968, entitled Metallurgical Furnace now abandoned.

This application discloses a metallurgical furnace having cover and base members, each of which is provided with a contact plate to directly heat and cool the edges of the coils. The seal of the present invention is especially adapted for use in this improved contact annealing furnace, although it can be employed in conventional prior art bell-type furnaces. One of the reasons for which it is especially adapted for use in the contact annealing furnace is that the contact annealing furnaces have walls on the cover and base members which are in telescoping relationship and may vary in their relative position depending upon the thickness of the coils being treated, and the seal of the present invention is well adapted to seal at the various axial positions which these telescoping walls may assume with any given furnace load. However, the simplicity of the construction of the present seal and its lack of certain undesirable characteristics of the prior art seals make it also well adapted for use in the prior art bell-type annealing furnaces.

SUMMARY OF THE INVENTION Briefly, the present invention contemplates the provision of a fluid inflatable seal for use between a cover section and a base section of a heat-treating furnace. The seal includes a fluid inflatable hollow annular member having inlet and outlet valves to supply and exhaust fluid to and from the annular member. The annular member is comprised at least in part of a nonelastomeric material. The seal is adapted to be inflated to a sealing position wherein it extends between a cover member and the base member in sealing relationship with both of them. The use of a nonelastomeric material prevents bulging and rupture at weak spots, such as is prone to happen I with rubber or other elastomeric materials when a portion thereof is confined and another portion is free to expand without restriction. Preferably, strips of relatively yieldable material are provided around the annular member to abut against both the cover and the base when the seal is in the expanded position to provide good sealing characteristics between the inflatable member and the cover and the base. In its inflated condition, the seal will provide an essentially fluidtight bearier against escape of the atmosphere from within the cover of the furnace and leakage of air from outside into the furnace.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a longitudinal sectional view, somewhat diagrammatic, showing the seal of the present invention incorporated in a contact-type annealing furnace;

FIG. 2 is a plan view of the base section of the furnace of FIG. 1 showing the seal of the present device in place;

FIG. 3 is a detailed sectional view of the seal and portions of the base and cover, with the seal in the collapsed position; and

FIG. 4 is a view similar to FIG. 3, with the seal in the expanded condition.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, and more particularly to FIGS. l and 2, the fluid inflatable seal of the present invention is shown incorporated in a metallurgical heat treating furnace designated generally as It). The furnace 10 includes a base section 12 and a cover section 114. The base section 12 in cludes three upwardly extending annular walls, 16, lit and 20, while the cover section includes two depending annular walls 22 and 24. The seal member generally designated at 26 is shown, positioned to seal between the upwardly extending wall 18 of the base 12, and the downwardly extending wall 22 of the cover 14. The seal 26 includes an annular inflatable ring member 28 which, as can best be seen in FIG. 2, completely surrounds the upstanding leg 18 of the base 112. The ring 28 is mounted to the legs 18 by means of a plurality of circum ferentially spaced flanged members 30.

The structure of the ring 28 and the mounting thereof to the flanges 30 is best seen in FIGS. 3 and 4.. Referring now to these two figures, the ring member 28 is formed with an inner hollow core 32 of elastomeric material such as natural or synthetic rubber, and an outer casing 34 which preferably is of a woven fabric and nonelastomeric. Inner and outer strips 36 and 38 respectively of relatively pliant yieldable material are provided on opposite sides of the outer casing 34. The strips of material 36 and 38 are adapted to seal respectively against the legs 22 and 18 when the seal is in the inflated condition as shown in FIG. 4. These strips are not necessary in all cases, since under many conditions the outer casing 34 may itself form a satisfactory seal.

The ring member 28 is suspended from the flanges 30 by means of tabs 40 engaging studs 42. Each of the tabs 40 is cemented to the casing 34 by an epoxy cement, and each has an eye (not shown) which slips over the stud 42. A nut 44 threads on each of the studs 42 to secure the tabs 40 in place.

Each of the flange members 30 has a laterally extending top portion 46 which extends outwardly over the inflatable ring member 28. As can be seen in FIGS. 3 and 4, this outwardly extending portion 46 extends beyond the outer edge of the ring member 28 when it is deflated, but the ring member 28 extends past the end of the overhang 46, in the inflated condition, to seal against the leg 22. With this configuration, if the overhangings 46 will protect the seal from damage when the cover is being emplaced or removed, as will become apparent presently.

In the preferred embodiment, the seal is adapted to be expanded by the use of water. In order to supply and exhaust water to and from the seal, a water control valve 18 is provided which communicates through a syphon valve 50 with a water supply valve 52. On the opposite side of the inflatable ring 28 is a metering orifice valve 54. When it is desired to expand the seal, water is supplied from the water supply valve 52 to the water control valve 48 with the syphon valve 50 inoperative. This will supply a flow of water to the ring member 28 to cause the ring member to expand. The metering orifice valve 54 is adjusted to allow water to discharge therethrough, but is sufficiently restricted so as to maintain a given pressure within the sealing ring 28.

The metering orifice valve 54 allows the water to flow into the trough formed between the legs 16 and 18, and the water will flow therefrom by means of an overflow drain pipe 56. The flow of water is provided to cool the seal when the furnace is heated to prevent the overheating of the seal. The overflow of the water into the trough also provides for a fluid seal around the leg 22 of the cover. When this fluid seal is provided, the sealing ring 28 provides a vapor barrier between the water in the trough and the'interior of the furnace, as well as sealing against the escape of gas from the interior of the furnace.

In order to deflate the seal, the metering orifice valve 54 is closed, and the syphon valve 50 is opened into the system. This will divert the flow of the water from the valve 52 to pipe 58, which will cause a syphoning action drawing the water The cover is then placed over the charge and lowered into place until it rests on the top of the coil. This will cause the legs 22 of the cover to telescope over into legs 16 and 18 of the base. During this motion, the extended portions 46 of the flanges 30 keep the cover centered and prevent the leg 22 from coming in contact with and damaging the ring 28. Once the cover is in place, the syphon valve 50 is cut out of the circuit and water is supplied from the supply valve 52 to the water control valve 48. The ring 28 will then expand, or inflate, which will push the pliant strips of material 36 and 38 into sealing engagement with the legs 22 at 18 as shown in FIG. 4.

In order to achieve a relatively good fluid tight gas seal, it may be necessary to inflate the ring 28 to a substantial pressure. Since the ring 28 is partially confined on opposite sides thereof, but relatively unrestrained on the top and bottom thereof, an elastomeric material under pressure differential would tend to bulge at these unrestrained portions. Hence, the use of the nonelastomeric woven outer casing 34 surrounding the elastomeric fluid tight inner casing 32. This outer casing 34 prevents and restrains any tendency toward bulging at the unconfined portions of the ring 28, but still allows for expansion and contraction of the seal.

Although the invention has been described in an embodiment adapted for use with water for inflating and deflating the hollow annular ring, the invention is also adapted for use with other liquids or air or other gas for inflation. Also, it is to be understood that, as indicated above, the use of the seal is not limited to this particular type of heat-treating furnace, but also is useful in other types of metallurgical furnaces having cover and base members which require a fluidtight seal such as belltype furnaces.

lclaim:

1. In a metallurgical furnace having a base section and a cover section disposed to rcmovably fit in telescoping relationship with each having normally radially spaced adjacent sealing surfaces, an improved seal comprising, an annular hollow fluid inflatable member carried by one of said sections and disposed to inflate to an inflated position wherein the member extends in lateral concentric sealing relation between the normally spaced sealing surfaces and, wherein said inflatable member is disposed in a deflated position when said annular member is collapsed, said annular member being formed at least in part of a nonelastomeric material disposed to limit its extent of expansion, and means to selectively supply and exhaust fluid to and from said annular member.

2. The invention as defined in claim 1 wherein guard means are disposed to protect said annular member when it is in the deflated position.

3. The invention as defined in claim 2 wherein said guard means includes flange means projecting from said one section to a location beyond the extension of said annular member in its deflated position.

4. The invention as defined in claim 1 wherein said annular member includes at least one strip of resilient deformable material disposed to seal against one of said sections.

5. The invention as defined in claim 1 wherein said means to exhaust fluid from said inflatable member includes means to create a partial vacuum in said annular members.

6. The invention as defined in claim 1 further characterized by said means to supply and exhaust fluid including valve means disposed to continually supply and discharge fluid from said inflatable member in the inflated position.

7. The invention as defined in claim 1 wherein said inflatable member includes a hollow core of elastomeric material and a casing surrounding said core of an essentially nonelastomeric material.

8. The invention as defined in claim 7 where said casing is'of woven fabric configuration. 

1. In a metallurgical furnace having a base section and a cover section disposed to removably fit in telescoping relationship with each having normally radially spaced adjacent sealing surfaces, an improved seal comprising, an annular hollow fluid inflatable member carried by one of said sections and disposed to inflate to an inflated position wherein the member extends in lateral concentric sealing relation between the normally spaced sealing surfaces and, wherein said inflatable member is disposed in a deflated position when said annular member is collapsed, said annular member being formed at least in part of a nonelastomeric material disposed to limIt its extent of expansion, and means to selectively supply and exhaust fluid to and from said annular member.
 2. The invention as defined in claim 1 wherein guard means are disposed to protect said annular member when it is in the deflated position.
 3. The invention as defined in claim 2 wherein said guard means includes flange means projecting from said one section to a location beyond the extension of said annular member in its deflated position.
 4. The invention as defined in claim 1 wherein said annular member includes at least one strip of resilient deformable material disposed to seal against one of said sections.
 5. The invention as defined in claim 1 wherein said means to exhaust fluid from said inflatable member includes means to create a partial vacuum in said annular members.
 6. The invention as defined in claim 1 further characterized by said means to supply and exhaust fluid including valve means disposed to continually supply and discharge fluid from said inflatable member in the inflated position.
 7. The invention as defined in claim 1 wherein said inflatable member includes a hollow core of elastomeric material and a casing surrounding said core of an essentially nonelastomeric material.
 8. The invention as defined in claim 7 where said casing is of woven fabric configuration. 